If you use automatic updates, sometimes you get the tray icon which notifies you that some Windows updates are available, so you accept to download them first, and install them later; then, sometimes the installed updates require you to restart the computer, but you want to postpone the reboot, and every few minutes you get the same annoying popup message requesting you to reboot. How to get rid of this message?
Just run services.msc and stop Automatic Updates service. It's as simple as that.